Quick-change lathe toolholder



y 1948- E. w. PLUMB QUICK CHANGE LATHE TOOL HOLDER 4 Sheets-Sheet 1 Filed June 21, 1946 INVENTOR fawnv W PL 0MB ATTORNEY July 20, 1948. I E. w. PLUMB QUICK CHANGE LATHE TOOL HOLDER Filed June 21, 1946 4 Sheets-Sheet 2 INVENTOR Eon/w W. PL (/MB ATTORNEY July 20, 1948. E. w. PLUMB 2,445,634

QUICK CHANGE LATHE TOOL HOLDER Filed June 21, 1946 4 Sheets-Sheet a INVENTOR Ebwuv w. PLu B ATTORNEY 4 Sheets-Sheet 4 Filed June 21, 1946 y H r I INVENTOR fowl/v N PLUMB ATTORN EY Patented July 20, 1943 OFFICE QUICK-CHANGE LATHE TOOLHOLDER Edwin W. Plumb, Morris, Conn. Application June 21, 1946, Serial No. 678,475

This invention relates to lathe tool holders, and more particularly to a quick change tool holder used for chucking operations in engine lathes.

One object of the present invention is to provide a device of the above nature which will be capable of interchangeably holding offset single pointed tools which must be adjusted laterally for boring, turning, facing, or cutting off operations, as well as tools such as drills and reamers which must operate in line with the axis of the lathe.

A further object of the present invention is to proxide a tool holder of the above nature having means for aligning the tools vertically with respect to the axis of the lathe.

A still further object is to provide a deviceof the above nature having means for changing tools rapidly and conveniently, and for returning them accurately to the same position in the holder for repetitive operations.

A further object is to provide means attachable to each individual tool or adaptor to permit rotative adjustment of said tool in the holder without changing the adjustment of the holder itself.,

A further object is to provide a tool holder of the above nature which will be simple in construction, inexpensive to manufacture, easy to in-.

stall and manipulate, rugged in construction,

compact, ornamental in appearance, and ,very.

efficient and durable in use. 7

With these and other objects in view, there have been illustrated on the accompanying drawings three forms in which the invention may 0011'- veniently be embodied in practice.

In the drawings,

Fig. 1 represents a fragmentatry. side view in elevation of a lathe upon which the first form of tool h'older embodying the-present invention has been installed.

Fig. 2 is an' end view of the first form of tool holder as it appears when attached to thelathe compound rest shown in dotted lines.

Fig. 3 is a top plan view of the same, showing the tool in dotted lines.

Fig. 4 is a rear view of the same.

Fig. 5 is an end view of an adaptor member for receiving a tapered shank tool, prior to clamping it in the tool holder.

Fig. 6 is a side view of the same. j

Fig. 71s an end view of a split bushing forre ceiving a cylindrical sh'ank tool prior to inserting it in the tool holder.

Fig. 8 is a side view of the same.

Fig. 9 is a perspective view of the same, with th adjusting collar removed.

3 Claims. (Cl- 82--36) Fig. 12 is a front view in elevation of a second form of tool holder having a quick-acting tool clamping and releasing device.

Fig. 13 is an end view of the same, showing how the tool holder is attached to the compound tool rest of a lathe.

Fig. 14 is a sectional view of the same, taken along the broken line l4l4 of Fig. 13, looking downwardly.

Fig. 15 is a fragmentary sectional view of the same, taken along the line |5I5 of Fig. 14.

Fig. 16 is a fragmentary sectional view of the same, taken along the line I6-l 6 of Fig. 14,1ooking upwardly.

Fig. 17 is a vertical sectional view of the same, taken along the line l of Fig. 13.

Fig. 18 is a front view in elevation of a third form of tool holder embodying the invention.

Fig. 19 is an end view of the same, showing in dotted lines the compound tool rest.

Fig. 20 is a sectional view of the same, taken along the broken line 29-40 of Fig. 19, looking downwardly.

Fig. 21 is a side view, in separated relation, of the compound screw and bushing employed with the third form of tool holder.

At present, engine lathe work involving repetitive operations on parts held in the lathe chuck, is apt to be a comparatively slow and clumsy process due to the difficulty in changing tools. Each tool change involves resetting the tool for center height and reestablishing its position relative to the cross slide. In drilling and reaming operations, the tools are held in the tailstock and fed laboriously by hand.

Numerous devices, such as cross slide turrets and tailstock turrets have been provided to speed up chucking operations in engine lathes, and work very well on certain classes of work. However, devices of this nature are not well adapted for holding both oifset outside turning tools, and drills, reamers, and similar tools.

The present invention is intended to provide a tool holder capable of permitting unlimited tool changes and which will be well adapted to hold either drills or offset turning and facing tools.

An operator using this improved tool holder will be provided with a number of tool adaptors having standardized shanks to fit the split tool block and holdin various tools for successive operations on the work. In the case of drills and boring bars, adaptors or bushings may be used which fit over the shanks thereof to adapt them to fit in the hole in the tool block. Since the holder is designed to clamp and release these adaptors and bushings quickly and permit them to be returned to the same relative positions when reinserted, the operator is enabled to perform successive operations with a minimum amount of time wasted in tool changes.

Referring now to the drawings in which like reference numerals denote corresponding parts throughout-the several views, and more particularly to the first form of the invention, shown in Figs. 1-4, the numeral 25 indicates a rectangular clamping bar which is adapted to be inserted ma T-slot 26 of a compound rest 21 ofa lathe 28, h

The first form of tool holder, which is indicated generally by the numeral T is providedwith a base member 29, which is adapted to be clamped in operating position by means of three headed vertical clamp screws 39,- 3 I 32, engaging the bar 25.

*In order to hold a tool adaptor or bushing (Figs. -9) in operating position, provision is made of a split block '34 having a horizontal hole 33 provided with an outer slot Ma, which block 36 may be adjusted parallel to the axis of the lathe by means (not shown) responsive to the angular adjustment means of the compound rest.

The split block 34 is attached to the base member 29 by means of a dove-tailed tongue 35 which maybe adjusted vertically in a dovetail groove 35a in the base 29 by means of a central elevating screw 36 to bring the center of said block into alignment with the axis of the lathe.

, The tool block -34 is adapted to be locked inverticallyadj-usted position by means of a vertical gib 39 which may be forced against the dovetailed tongue 35 by means of a pair of set screws 48, 4|. M k 7 Provision is also made on the base 29 of a narrow top plate 31 for supporting the elevating screw 36 and covering the base member 29. A collar 38 under the top plate 31 is secured to the screw 36 by a pin'38a in order to hold said screw against accidental vertical movement (Fig, 2).

The adaptors and bushings (Figs. 5-9) for the tools operating on the work in the lathe 'will be provided with cylindricalshanks which may be inserted into the cylindrical recess 33 of the split tool block 36, and clamped securely therein by tightening a pair of cap screwsfl. 43 which contract the-sides of the split toolblock 34 sufficiently to produce the desired clamping action. A

A central releasingscrew 44 is located between the screws d2, 43, being threaded into the top portion of the splittoolblock lifl and bears against the bottom portion of said block, so that after said cap screws 52, 53 are loosened, the screw fl maybe rotated to expand the tool block sufiiciently to permit removal of the tool therefrom.

4 In order to hold the tool against turning under the torque due to the cutting action of the lathe tools, provision is made of a pair of vertically aligned keys 45, 45a, integra'l wi th the block 34 and'adapted to engage in suitablejkeywa ys the adaptors or bushings clamped in said block. These keys as, t'sa in insure t at the tools 111 be returned to the tool holder in exactly the same radial position a each time they are inserted therein. 7 H c p p Figs?) and 6 of the drawing illustrate a flanged adaptor I20 for holding "taper shank 'dr ills, reamers, "and other multiple edge cutting tools which serves to hold a cylindrical boring bar B,

as shown; in;Fig. 1-1. The bushing I25 is adapted to be clamped upon the boring bar B (Fig. 11) after the bar has first been adjusted to the desired center height and longitudinal position in saidbus'hing by a cap screw I26 mounted in a detachable split collar I21 provided with a guide hole I28 which is adapted to receive the side pin 88 on the tool block'Bfl shown in Figs. 1 7.

Second form of theimaeiition In the second form of the invehtibnshowndn Figs. '12-17 a modified form of hollow tool block 60 is 'slidably attached to a base clamping meniber'fil by means of a verticaldovetail tone 62 which is "adjustable in a dov'etail' grocjve' 62a 'by'a vertical *e1evati'ng screw'es. Tlfi 'dbvjt'lil tongue 62 is clamped to the base member'fi I by means "of a clamping bar 64 of trapezoidal cross section The clamping bar 6'4 is adapted tofb'e drawn into firm engagement wither; angular surface of the tool block '60 bymeans'o'f a pairef h'orizontal clamping screws"6 6,'51 w H L In this form or the invention. the meek-an has an interior "cylindrical recess Gllb' ih'wliidh theftool adaptor or bushingis held by a quiet-acting clamping device which 'allo'Wsit to be gripped or released rapidly and conveniently. "Thetool block 60 is split lengthwise to providea slot lilld'which ermits the bldck BIT t0 be selectively contracted or expanded under the action of the ee'viee no'w to be described. V "v A horizontal cain shaft '68 provided "with-an tegral handle arr'n B'Q a't rightfarigle's the tendsthrough the 'to'ol'bloc'k 6 0 a l'ong'itu nal direction, and is rotatable thereh. Thes haftflr fl is restrained against 'endwise money; by means of a shoulder screw IBcarridfb'y -the 'bloc k fifl' and located-in a, groove I 9 insaid'shaft 6B.

The shaft 60 is a'ls'o provided withjhree eesetric'car'ns Iii, I I, "l z-the'end'eccentr s I'Il, passing through the upper ends of a pa r;crvertical parallel links I3, I4 which are a apted tofbe pulled upwardly by a'partial turniof'thehandle 6'9 to'contractthesplit'blockfiiLsiightly- N a The "end links 13, I4 are fitted intoa'pai'r'of vertical open slots I5, 15, and 'II, II'a"formedfin the front of the tool block f'GIl, and said are secured to the lower end ot-thatch bi'ock 60 by a pair of horizontal pins 80, 8] whichpas's through elongated slots 82, 8'3inf1inks 13fll4. V

In order to adjust the clampingaction of"the links I3, I I a pair of vertical set 'serewsg'ai, '85 are threaded into the lowerends thereofand bear upon the pins 80, 8|. i v

The central eccentric II engages a vertical plug 86 mounted in the blockfill insu'cha mannor that said plug Will be depressed When' the handle 69 is rota'ted'in the "epposite'e'irectibn, causing the split sections'oftlieftoolblobk Iill to be spread apart, enabling the tdo'lstobe easily removed from thecylindrical "recessbllb. "The plug 86 may be adjusted by a set screw 81 as desired.

Third form In the third form of the invention shown in Figs. 18-21 a split tool block IN is slidably mounted vertically on a base I02 by means of two cooperating angled ways I03, I04. The angular surfaces of said ways are clamped together by means of a pair of horizontal bolts I05, I06 and the vertical adjustment of the tool block may be varied by turning an elevating screw I01. The base I02 is provided with a pair of vertical slots I 08, I09 to permit adjustment in the vertical positions of the clamp screws I05, I06.

The tool block I is split with a horizontal slot l0 Ia to permit the clamping of tool adaptors in a cylindrical recess H0. The clamping action in this form of holder, however, is obtained by the use of a pair of compound screws III, I I2,

both of which are provided with left hand threads on their upper larger ends, and with right hand threads on their lower smaller ends.

Provision is also made of a pair of bottom bushings H3, H4, which are threaded exteriorly to engage in tapped holes in the lower part of the split tool block IN, and tapped internally to engage the lower small right hand threaded sections of the screws I l l, H2.

As in the first two forms of the invention, the tool holder base I02 is attached to the T-slot N5 of the compound rest H6 by means of a clamping bar II'I held in place by three vertical headed clamp screws I I8, I I9, I20.

In the assembly of the parts of the third form of the invention, the screws II I, I I2 will be first inserted in the top section of the tool block WI. The bushings II3, I I4 will then be inserted in operating position in the lower section of said tool block and twisted into engagement with the screws III, H2.

One advantage of the present invention is that by reason of the great reduction in tool-changing time it will make possible rapid production on engine lathes, approaching that of turret lathes.

While there have been disclosed in this specification three forms in which the invention may be embodied, it is to be understood that these forms are shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosures, but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new, and for which it is desired to secure Letters Patent, is:

1. In a lathe tool holder, a base for attachment to the compound rest of the lathe, a split block having a horizontal hole to receive the lathe tool or adaptor therefor, means to adjust the vertical position of said block with respect all] to said base, and means to selectively contract the sides of said block upon said tool or expand said sides to release said tool, comprising a manually-rockable shaft fitted into the upper portion of said block, said shaft having three eccentric cams, means to connect the two end cams to the bottom portion of said block, whereby when said shaft is rocked in one direction the sides of said block will be contracted, and means located in said lower block and engageable by said central cam to expand the sides of said block and release the tool mounted therein.

2. In a lathe tool holder, a base for attachment to the compound rest of the lathe, a split block having a horizontal hole to receive the lathe tool or adaptor therefor, means to adjust the vertical position of said block with respect to said base, and means to selectively contract the sides of said block upon said tool or expand said sides to release said tool, comprising a horizontal manually rockable shaft fitted into the upper portion of said block, said shaft having a pair of cams, a link surrounding one of said cams, and means to connect said link to the lower portion of said block, means mounted in said lower portion engageable by said other cam, whereby the rocking of said shaft in one direction will contract said block, and the rocking of said shaft in the other direction will expand said block.

3. In a lathe tool holder, at base for attachment to the compound rest of the lathe, a split block having a horizontal hole to receive the lathe tool or adaptor therefor, means to adjust the vertical position of said block with respect to said base, and means to selectively contract the sides of said block upon said tool or expand said sides to release said tool, comprising a rockable shaft fitted in the upper portion of said block, said shaft having an eccentric cam, a link having a circular aperture near its upper end loosely surrounding said cam, said link having a vertical slot near its lower end, a cross rod located in said slot and mounted in the lower portion of said block, and a. set screw in the lower portion of said block for engaging said cross rod to adjust the position of said link.

EDWIN W. PLUMB.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 70,830 Gleason Nov. 12, 1867 609,767 Bailey Aug. 30, 1898 643,713 Converse Feb. 20, 1900 965,893 Hanson Aug. 2, 1910 1,314,911 Stephenson Sept. 2, 1919 1,454,611 Adair May 8, 1923 2,171,802 Nielsen Sept, 5, 1939 2,345,161 'I'homason Mar. 28, 1944 2,361,683 Greenberg Oct. 31, 1944 2,390,148 Hymans Dec. 4, 1945 

